Work-Process for links with different origins / grasshopper referencing

Hey everyone;

I stumble accross a file project management issue - and I am just curious to know if there is a better solution to what i did as i found myself locked with no satisfactory results. Let me explain what I am trying to achieve :

As an architect, I have receiveid a CAD (.dwg) survey drawing millions mms away from the origin point - I assume that’s the way the surveyer works in this part of the world (probably part of a local referencing system) - and because it is an input i do not plan/want to edit this file : it is the coordinates system we share with all consultants (structural engineers, etc…) for lining-up models.

I want to build 2 rhino file (both in mm)

  • one for the site (in which I insert my survey as a link to build up site)
  • one for the my project (modeling, grasshoppering, rendering)

The model-site is okay millions mm away from the origin : I can model and also place C planes if i want to work with “local units” (despite having always tried to work close to 0,0,0 in rhino… as it tends to get buggy when you are far away from the file origin.) So that is a file that I can share with other team members that matchs our “corrdinates reference system” .

However for the project-file I thought I would model close to 0,0,0, because I am also using grasshopper, and as said before : as a general rule I try to keep my model close to 0,0,0… To do so I inserted (link-reference) my site model in my project model - so i can control it relative position.
So far so good, except :
1 - I cannot get any data from my site-model (linked-reference) in my grasshopper file because it is a link (grasshopper being open in the project-file)
2 - My project-model is not using the common “coordinates reference system” the Project teams work with. So when I want to whare this model - I need to move my model.

I would love to work in a similar fasion as revit shared coordinates - but as far as I know, there is no equivalent in Rhino.

I am aware of worksessions, used it sometimes for projects, and I would have prefered to use it - but as far as I know that means that i need to have my project-file millions mm units away from 0,0,0 so it lines up with the site and the common “coordinates reference system” the project teams work with - again I was always told to keep my project-file close to 0,0,0 to avoid operation bugs - renders bugs, etc…

One may say I could move my model everytime I want to export my project-file… but I believe its gives room for error.
As for Grasshopper I could grab datafrom my site-model, internalise it and pass it over to my project-grasshopper.

Overall, i just think these workaround are not the best way to work - Yet that is exactly what I have been doing so far.

Has anyone thought about this and the most efficient way ?

PS : Did not post any projects files as I thought it is more of a conceptual problem and the project cannot be shared, but let me know if you would like to have it, I can replicate my set-up for you if need be !

Thanks for reading

1 Like

I agree!

At least as a quick fix give worksession the option of “insertion point” like insert blocks.
As architects we often reference dwg files from another coordinate system. A function describes by @gandolphe.thomas is essential for us.


Well it seems we all stumble upon the same issue here… I am sure it will be adressed some day. Thanks